mcp3008::LineSensor Class Reference

The LineSensor device, based on MCP3008 chip. More...

#include <mcp3008_linesensor.h>

Inheritance diagram for mcp3008::LineSensor:

Classes
struct	CalibrationData
	The LineSensor's calibration data. More...

Public Member Functions
struct mcp3008::LineSensor::CalibrationData	__attribute__ ((packed))
	LineSensor ()
virtual	~LineSensor ()
LineSensorCalibrator	startCalibration ()
	Start the sensor line calibration procedure. More...
const CalibrationData &	getCalibration () const
	Get the calibration data used by linesensor, feel free to save this structure somewhere and load it afterwards using setCalibration(). More...
bool	setCalibration (const CalibrationData &data)
	Set calibration data used by the line sensor. More...
float	readLine (bool white_line=false, float line_threshold=0.20f) const
	Try to determine a black line's position under the sensors. More...
esp_err_t	calibratedRead (std::vector< uint16_t > &results) const
	Same as Driver::read(), but returns calibrated result if possible. More...
esp_err_t	calibratedRead (uint16_t *dest) const
	See the other calibratedRead(std::vector<uint16_t>&) const method. More...
uint16_t	calibratedReadChannel (uint8_t channel, esp_err_t *result=nullptr) const
	Same as Driver::readChannel(), but returns calibrated data. More...
Public Member Functions inherited from mcp3008::Driver
	Driver ()
virtual	~Driver ()
	The uninstall() method is called from the destructor. More...
esp_err_t	install (const Config &cfg=Config())
	Initialize the SPI bus. Must be called before any other methods, otherwise they will return ESP_FAIL. More...
esp_err_t	uninstall ()
	Free the SPI bus. Must be called last, or other methods return ESP_FAIL. More...
uint8_t	getChannelsMask () const
	Get the channel mask, specified in Config::channels_mask. More...
esp_err_t	read (std::vector< uint16_t > &results, bool differential=false) const
	Read values from the chip. Returns values in range <0; Driver::MAX_VAL>. More...
esp_err_t	read (uint16_t *dest, bool differential=false) const
	See the other read(std::vector<uint16_t>&, bool) const method. More...
uint16_t	readChannel (uint8_t channel, bool differential=false, esp_err_t *result=nullptr) const
	Read a single channel from the chip. Returns value is in range <0; Driver::MAX_VAL>. More...

Additional Inherited Members
Static Public Attributes inherited from mcp3008::Driver
static constexpr int	CHANNELS = 8
	Amount of channels on the chip. More...
static constexpr uint16_t	MAX_VAL = 1023
	Maximum value returned by from the chip (10bits). More...
Protected Member Functions inherited from mcp3008::Driver
int	requestToChannel (int request) const

Detailed Description

The LineSensor device, based on MCP3008 chip.

This class is not thread-safe, you have to make sure the methods are called from one thread at a time only.

Constructor & Destructor Documentation

LineSensor()

mcp3008::LineSensor::LineSensor

(

)

~LineSensor()

mcp3008::LineSensor::~LineSensor ( )

virtual

Member Function Documentation

__attribute__()

struct mcp3008::LineSensor::CalibrationData mcp3008::LineSensor::__attribute__

(

(packed)

)

calibratedRead() [1/2]

esp_err_t mcp3008::LineSensor::calibratedRead

(

std::vector< uint16_t > &

results

)

const

Same as Driver::read(), but returns calibrated result if possible.

Parameters

results

the results will be APPENDED to this vector. It will be unchanged unless the ESP_OK result is returned (except possibly its capacity). Between 0 and Driver::CHANNELS values are appended, depending on Config::channels_mask.

Returns

ESP_OK or any error code encountered during reading. Will return ESP_FAIL if called when not installed.

calibratedRead() [2/2]

esp_err_t mcp3008::LineSensor::calibratedRead

(

uint16_t *

dest

)

const

See the other calibratedRead(std::vector<uint16_t>&) const method.

Parameters

dest	array MUST be big enough to accomodate all the channels specified by Config::channels_mask!

calibratedReadChannel()

uint16_t mcp3008::LineSensor::calibratedReadChannel	(	uint8_t	channel,
		esp_err_t *	result = nullptr
	)		const

Same as Driver::readChannel(), but returns calibrated data.

Parameters

result

result code will be written here, may be null.

Returns

measured value or 0xFFFF on error.

getCalibration()

const CalibrationData & mcp3008::LineSensor::getCalibration ( ) const

inline

Get the calibration data used by linesensor, feel free to save this structure somewhere and load it afterwards using setCalibration().

Returns

CalibrationData reference

readLine()

float mcp3008::LineSensor::readLine	(	bool	white_line = false,
		float	line_threshold = 0.20f
	)		const

Try to determine a black line's position under the sensors.

Parameters

white_line	the line is white on black background instead of default black on white background.
line_threshold	values above this threshild will be considered "on the line". At least one sensor has to have value above this threshold, otherwise NaN is returned. The value is a fraction, 0.20 == 20% == (1023*0.20) == 200.

Returns

A number in range <-1,1>, where -1 means the line is under the channel with smallest ID, 0 means in the middle and 1 means it is under the one with the greatest ID. Examples, assuming using 8 channels:
-1.0: under channel 0
0.0: under channel 3-4
1.0: under channel 7
Returns NaN when the line is not found (see line_threshold).

setCalibration()

bool mcp3008::LineSensor::setCalibration

(

const CalibrationData &

data

)

Set calibration data used by the line sensor.

Parameters

data	the calibration data obtained previously from getCalibration().

Returns

if the result is false, calibration data were invalid (out of range)

startCalibration()

LineSensorCalibrator mcp3008::LineSensor::startCalibration

(

)

Start the sensor line calibration procedure.

Returns

LineSensorCalibrator object used for calibration.

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The documentation for this class was generated from the following files:

• mcp3008_linesensor.h
• mcp3008_linesensor.cpp